Refactor jsdoc merging

Author: danez

packages/react-docgen/src/Documentation.ts

@@ -10,11 +10,13 @@ export interface Documentation {
 
 export interface MethodParameter {
   name: string;
+  description?: string;
   optional: boolean;
   type?: TypeDescriptor<FunctionSignatureType> | null;
 }
 
 export interface MethodReturn {
+  description?: string;
   type: TypeDescriptor<FunctionSignatureType> | undefined;
 }
 

packages/react-docgen/src/handlers/__tests__/__snapshots__/componentMethodsJsDocHandler-test.ts.snap

@@ -16,12 +16,10 @@ exports[`componentMethodsJsDocHandler > adds descriptions 1`] = `
         "description": "The test",
         "name": "test",
         "optional": false,
-        "type": null,
       },
     ],
     "returns": {
       "description": "The number",
-      "type": null,
     },
   },
 ]
@@ -39,7 +37,6 @@ exports[`componentMethodsJsDocHandler > adds js doc types when no flow types 1`]
     "name": "foo",
     "params": [
       {
-        "description": null,
         "name": "test",
         "optional": false,
         "type": {
@@ -48,7 +45,6 @@ exports[`componentMethodsJsDocHandler > adds js doc types when no flow types 1`]
       },
     ],
     "returns": {
-      "description": null,
       "type": {
         "name": "string",
       },
@@ -69,7 +65,6 @@ exports[`componentMethodsJsDocHandler > keeps flow types over js doc types 1`] =
     "name": "foo",
     "params": [
       {
-        "description": null,
         "name": "test",
         "optional": false,
         "type": {
@@ -78,7 +73,6 @@ exports[`componentMethodsJsDocHandler > keeps flow types over js doc types 1`] =
       },
     ],
     "returns": {
-      "description": null,
       "type": {
         "name": "number",
       },

packages/react-docgen/src/handlers/componentMethodsJsDocHandler.ts

@@ -5,21 +5,25 @@ import type {
 } from '../Documentation.js';
 import type { Handler } from './index.js';
 
+function removeEmpty<T extends Record<string, unknown>>(obj: T): T {
+  return Object.fromEntries(
+    Object.entries(obj).filter(([, v]) => v != null),
+  ) as T;
+}
+
 // Merges two objects ignoring null/undefined.
-function merge<T, U>(obj1: T, obj2: U): (T & U) | null {
+function merge<
+  T extends object | null | undefined,
+  U extends object | null | undefined,
+>(obj1: T, obj2: U): (T & U) | null {
   if (obj1 == null && obj2 == null) {
     return null;
   }
-  const merged: Record<string, unknown> = {
-    ...(obj1 as Record<string, unknown>),
+  const merged = {
+    ...removeEmpty(obj1 ?? {}),
+    ...removeEmpty(obj2 ?? {}),
   };
 
-  for (const prop in obj2 as Record<string, unknown>) {
-    if (obj2[prop] != null) {
-      merged[prop] = obj2[prop];
-    }
-  }
-
   return merged as T & U;
 }
 /**